1 files changed, 70 insertions, 0 deletions

diff --git a/fs/proc/devices.c b/fs/proc/devices.c
new file mode 100644
index 000000000000..59ee7da959c9
--- /dev/null
+++ b/fs/proc/devices.c
@@ -0,0 +1,70 @@
+#include <linux/fs.h>
+#include <linux/init.h>
+#include <linux/proc_fs.h>
+#include <linux/seq_file.h>
+
+static int devinfo_show(struct seq_file *f, void *v)
+{
+        int i = *(loff_t *) v;
+
+        if (i < CHRDEV_MAJOR_HASH_SIZE) {
+                if (i == 0)
+                        seq_printf(f, "Character devices:\n");
+                chrdev_show(f, i);
+        }
+#ifdef CONFIG_BLOCK
+        else {
+                i -= CHRDEV_MAJOR_HASH_SIZE;
+                if (i == 0)
+                        seq_printf(f, "\nBlock devices:\n");
+                blkdev_show(f, i);
+        }
+#endif
+        return 0;
+}
+
+static void *devinfo_start(struct seq_file *f, loff_t *pos)
+{
+        if (*pos < (BLKDEV_MAJOR_HASH_SIZE + CHRDEV_MAJOR_HASH_SIZE))
+                return pos;
+        return NULL;
+}
+
+static void *devinfo_next(struct seq_file *f, void *v, loff_t *pos)
+{
+        (*pos)++;
+        if (*pos >= (BLKDEV_MAJOR_HASH_SIZE + CHRDEV_MAJOR_HASH_SIZE))
+                return NULL;
+        return pos;
+}
+
+static void devinfo_stop(struct seq_file *f, void *v)
+{
+        /* Nothing to do */
+}
+
+static const struct seq_operations devinfo_ops = {
+        .start = devinfo_start,
+        .next  = devinfo_next,
+        .stop  = devinfo_stop,
+        .show  = devinfo_show
+};
+
+static int devinfo_open(struct inode *inode, struct file *filp)
+{
+        return seq_open(filp, &devinfo_ops);
+}
+
+static const struct file_operations proc_devinfo_operations = {
+        .open           = devinfo_open,
+        .read           = seq_read,
+        .llseek         = seq_lseek,
+        .release        = seq_release,
+};
+
+static int __init proc_devices_init(void)
+{
+        proc_create("devices", 0, NULL, &proc_devinfo_operations);
+        return 0;
+}
+module_init(proc_devices_init);